In the field of suspension of automobile vehicles, it is known to obtain a connection between the right side and the left side of the vehicle, generally by means of using a torsion bar often called "antiroll bar", so that overloading that occurs on one side of the vehicle can be partially supported by the other side of the vehicle. It is thus obtained, by means of a slight stiffening of the suspension, improved riding qualities of the vehicle, particularly in the case of lateral overloading and an improved dynamic aspect of the vehicle of which the body thus remains substantially parallel to the ground even on sloped surfaces, that correspondingly reduces risks of overturning and rolling. On the other hand, it is sought to reduce the pitch of the vehicles which is apparent from oscillations from front to rear and vice versa, especially by a dipping of the front during braking. This dipping of the front is particularly troublesome on motorcycles where it is known as "jump" or "bow". Its reduction can be carried out by a mechanical connection between the front and rear suspensions gears of the vehicle that are relatively far apart from each other.
In order to obtain the connection between the front and rear suspensions, it has already been proposed to assemble the front and rear suspensions in a single housing and to have them compressed by means of links mechanically connected to suspension arms of the wheels, but this compact and advantageous disposition of the front and rear suspension springs does not produce an effective connection for correcting the rolling or "jumping or bowing" movements of the vehicle.